Were the problems reported for the game itself (installer integrity check stalling, black screens when starting game, etc.) also adressed or just the shelf mix up?

Yep, that worked. Thanks :)

Yeah, I did another refresh and reload and the problem sorted itself out a few minutes ago.

How do you refresh your account? Logout and sign back in?

You click the following link:
https://secure.gog.com/en/account/refresh

while logged in, just open a tab with https://www.gog.com/account/refresh

edit: a ninja cat beat me

From MaGog's logs for 5 May:

As mentioned by Judas, GOG has reverted the game ID for Shadow Warrior (2013) to its previous value. Here is what got lost from the game page as result of that:
- Italian is no longer listed under languages
- PEGI Rating is missing
- Mac System Requirements are missing
- Linux System Requirements are missing
- Windows System Requirements changed from
*** “Windows XP / Vista / 7 / 8, Processor: 2.4 GHz Dual Core Processor or higher, Memory: 2 GB RAM, Graphics: ATI Radeon HD 3870/NVIDIA 8800 GT or better, DirectX: Version 9.0c, Hard Drive: 15 GB available space, Additional Notes: An unabashed love of katanas is preferable, Recommended system requirements: Windows 7 SP1 64-bits, Processor: Intel Core 2 Quad 8200 / AMD Phenom X4 9950, Memory: 4 GB RAM, Graphics: ATI Radeon HD 4890 / NVIDIA GeForce GTX 460 or better, DirectX: Version 11, Hard Drive: 15 GB available space, Additional Notes: The will of a true ninja warrior and an appreciation of Wang jokes”
To
*** “XP / Vista / 7 / 8, 2.4 GHz Dual Core Processor or higher, 2GB RAM, ATI Radeon HD 3870/NVIDIA 8800 GT or better, DirectX9.0c, 5GB of available HD Space”





NOTE! CHANGED FILE Independence War 2: Edge of Chaos, downloadables, Windows installer, English (setup_independence_war2_2.0.0.6.exe ***TO*** setup_independence_war2_2.1.0.9.exe; Tue, 21 Jan 2014 01:34:34 GMT ***TO*** Thu, 30 Apr 2015 16:29:07 GMT; 994,346,640 ***TO*** 995,572,536)





NOTE! CHANGED Celtic Kings: Rage of War, sys_req_win: Windows XP or Windows Vista, 1 GHz Processor (1.4 GHz recommended), 256MB RAM (512 recommended), 3D graphics card compatible with DirectX 8.1 (compatible with DirectX 9 recommended), Mouse, Keyboard ***TO*** Windows XP or Windows Vista, 1 GHz Processor (1.4 GHz recommended), 256MB RAM (512 recommended), 3D graphics card compatible with DirectX 8.1 (compatible with DirectX 9 recommended), Mouse, Keyboard, Minimum resolution notice: A minimal screen resolution of 1024 x 768 is required





NOTE! CHANGED Pacific General, sys_req_mac: OS X 10.7 or later. Processor: Intel Core Duo 2GHz+ Memory: 1GB of RAM Graphics: 64MB of video memory Recommended two-button mouse, or Apple mouse with Secondary Button / Secondary Click enabled ***TO***

NOTE! CHANGED Pacific General, sys_req_linux: Ubuntu 14.04, Linux Mint 17, Processor: 2.0 GHz, Memory: 1 GB RAM, Graphics: 256 MB VRAM, OpenGL compatible ***TO***

[GOG game page bug fix, as the game only supports Windows]





NOTE! CHANGED Witcher 2: Assassins Of Kings, The - Enhanced Edition, os: Windows (XP, Vista, 7, 8) and Mac OS X (10.7.5 or newer) and Linux (Ubuntu 14.04, Mint 17) ***TO*** Windows (XP, Vista, 7, 8) and Mac OS X (10.8.5 or newer) and Linux (Ubuntu 14.04, Mint 17)

NOTE! CHANGED Witcher 2: Assassins Of Kings, The - Enhanced Edition, sys_req_mac: OS X 10.7.5 or higher, Intel Core 2 Duo, 4 GB RAM, GeForce GT 650M 512MB (on 1440x900, low) or Radeon HD 5770 1GB (on 1440x900, low), 25 GB HD space. Please note: Nvidia is constantly perfecting the graphics drivers for Mac Book Pro with the Nvidia 650M Graphics Card. Until they provide an update the performance in the game on Macs with 600 Series nVidias may not measure up to usual levels, Recommended system requirements: OS X 10.7.5 or higher; Quad Core Intel; 8 GB RAM; GeForce GT 650M 1GB (on 1440x900, low) or Radeon HD 6970M 1 GB (on 1920x1080, medium); 25 GB HD space. Please note: Nvidia is constantly perfecting the graphics drivers for Mac Book Pro with the Nvidia 650M Graphics Card. Until they provide an update the performance in the game on Macs with 600 Series nVidias may not measure up to usual levels ***TO*** OS X 10.8.5 or higher, Processor: Intel Core 2 Duo, Memory: 4 GB RAM, Graphics: GeForce GT 650M 512MB (with 1440x900, low) or Radeon HD 5770 1GB (with 1440x900, low) or Intel Iris Pro 5200, Hard drive space: 25 GB HD space, Recommended system requirements: OS X 10.8.5 or higher, Processor: Quad Core Intel, Memory: 8 GB RAM, Graphics: GeForce GTX 675MX 1GB (with 1920x1080, medium) or Radeon HD 6970M 1 GB (with 1920x1080, medium) or Intel Iris Pro 52000, Hard drive space: 25 GB HD space

I recently read a post by a GOG rep. about some feature or other currently going through "QA" and had a good belly laugh.

Just figure out a way to put mrkgnao on the payroll without having to re-locate him to Poland, make sure nothing gets approved for publication without mrkgnao's say so, and let us all reap the benefits!

Your system might even get tweaked to catch the obvious mistakes before they even need to be reviewed...

I think there are a lot of people who would improve GOG's QA massively if you subbed them into that sentence.

Says the guy I personally recommended to GoG's staff for proper Linux builds.

Wouldn't be the first time either.

I'd love to work for GoG... :) Although my programming experience is rusty, I could still do great SQL lines when need be and otherwise be helpful as an assistant similar to Judas.

And I'm great with just about anything QA/UI/UX-related... I just can't travel to Europe because of my risk-averse personality and financial situation.

That reminds me. I really have to get around to writing the requisite test suites so I can feel confident in publishing my pack of guidelines and tools for building good .tar.gz release bundles.

In case you're curious, I've attached a couple of screenshots from the draft guidelines. (I censored the project name to maximize the chances that I remain the only Google result on release day.)